Bicycle frame



FIG. 1 is a perspective view of a bicycle frame showing our new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front elevational view thereof; and,

FIG. 7 is a rear elevational view thereof. 

The ornamental design for a bicycle frame, as shown and described. 